Disinfection is a critical process step in potable water treatment. Chlorine is currently the most widely used, and least costly disinfectant. An unfortunate by-product of chlorine disinfection is the formation of carcinogenic trihalomethanes (THMs) when chlorine reacts with organics dissolved in water. A further disadvantage of chlorine is its inability to remove viruses. Ozone is a more powerful disinfectant that can destroy viruses, and whose use is well proven in water treatment. Its high cost, however, has severely limited its widespread use. This proposal will demonstrate that unique perfluoro -membranes have properties that enhance water ozonation. These membranes are nonporous and resist clogging, are chemically inert to ozone, and have 30 times the flux rate of other nonporous membranes. The postulated mechanism of ozone transfer from the membrane into water is such that it may bypass or minimize the normally rate limiting gas- liquid transfer step. If successful, development of much improved ozone injection devices would eliminate much of the cost disadvantage of ozone treatment and allow wider use of this intrinsically advantageous disinfectant, with an associated reduction in the incidence of cancer due to THMs. This technology would be equally useful for the final stage of wastewater treatment. PROPOSED COMMERCIAL APPLICATION: Our unique perfluoromembrane has properties that enhance water ozonation and narrow the cost of ozone verses chlorine water treatment. increased use of ozone as a disinfectant would eliminate the formation of carcinogenic THMs in drinking water and reduce cases of viral illness caused by water contamination, thereby contributing to a reduction of the nation's health bill for treatment of cancers and certain viral diseases.